add triu/tril (get upper/lower triangular parts of a square matrix)
Merge branch 'develop' of github.com:ghorn/casadi into ghorn-develop
Better sparsity pattern calculation #1021
Added Matrix::setSparse #1021
tril(GenericMatrix), triu(GenericMatrix) using setSparse #1021
Fixed printing of set_sparse
Removed square restriction for tril(GenericMatrix), triu(GenericMatrix) #1021